Process for the conversion of asphaltic hydrocarbons



V.V A. SLMI 3m. E3, E942.

2,269,485 PROCESS l'OR THE CONVERSION OF ASPHALTIC HYDROCARBONS Filed Jan. 9, 1940 F04 THR FIRM ,4free/vars.

Patent-ed Jan. lf3,

PROCESS FOR THE CONVERSION YF l ASP-BALTIC HYDROCARBONS Y vaines. salmi, Culver city, cam., assign@ ,to

Metallytic Corporation, Los Angeles,` Calif., a, corporation ofCalifornia Application Januar-ys, 1940, sei-alim. 313,034 v y 1o claims.. gorras-1o) l l' VAl simple, economical process-fori vthe complet This invention relates tothe conversion,"of

sphalt or asphalt-like hydrocarbons into hydrir'`l` :arbon oils falling within the boiling point range t lubricating oils; this conversion being accomnlished by a simple heat treatment, without the dditionof hydrogen'or use of chemicals.` 'I'hese lsphaltic hydrocarbons occurv in nature either is such or together with lighter hydrocarbons n petroleum, also in the'destructive distillation roducts of coal, shale, peat, wood, etc. In such roducts and especially in petroleum, asphaltlc odies form the least valuable constituent and n the refining of such products for variousl inlustrial uses', the asphalt presents one of the- ,Teatest problems not only from a purely techni-A 1al, but also from a commercial viewpoint.

Thus, in the separation of the various constitlents of petroleum by distillation, not only are he asphaltic bodies separated with diillculty rom the most valuable fractions; that is, the ieavy lubricating oils, but the tendency is for he lubricating Voil fractions to revert into lsphalt. Moreover, the asphaltic residues may e disposed of only as low grade fuel oils or as he least desirable raw stock for cracking procsses. In the cracking of the asphalticoils witha "lew of producing lighter motor fuels, formation,

f coke and noncondensabie gases soon sets in, esnlting in a yield of gasoline lower than what would be theoretically expected, taking into conlderation the hydrogen content of the original tock. When overhead stocks such as kerosene, :as oil or lubricating oils are used as starting maerial, a much more satisfactory decomposition eaction rst takes place, but eventually asphalt ormation sets in, resulting lultimately in th'e fornation of coke and non condensable gases, where- Iy valuable hydrogen islost. l,

In milder cracking operations, where effort is cade to convert residualv oils into fuel oil of uwer viscosity, into oil stock more suitable for ntensive cracking operations, or even into lubriating oil, the processes now known are capable f only partial conversion of asphalt, if the actul asphalt content of the stock is taken into conlderatlon. Moreover, if recovery of lubricating ils or other valuable oil fractions is attempted as separate distillate, a large part of the stock forked upon will remain as residue of less value han the original stock and unilt for further nnversion by the same process, except under onditions where coke and gas formation takes lace.

"lubricating oil boiling point range,j'byf.a.'g-simple heat treatment 'without theuse of :hydrogenarid-V values, b ut also from the'vieWpOintof'overcom-' ingrefining diiculties and reducing theare'finingl i cracking operations; Y I

conversion of asphaltic bodies lntoollsg-off'thef without.y any appreciable loss or'vi'ormation` of fany.- undesirable by-products, would.t.herefore-'bev`al uable, not only froml 'thevievvpointfofflubricating.i

losses and from'the viewpoint oflproducingysuw Derior fuel oils'andmore desirable` tocks'for.

it is an objectA of my inventionrto :rovideca: method of simple and'eilicient. character ,wherea "by vheavy hydrocarbons may 'be converted pinto;y

lighter hydrocarbons and-'whereby-asubstantial l conversin yof asphalt or asphalt-like'residues j into lubricating. ofilqniay be obtained-by pyrolytic treatment, and in general to provide la-hydrocarv f hon conversion method for the'manufacturexotr4 lubricating oils, fuel oils, or overhead cracking stocks of superior quality.

If have discovered that if asphaltichydrocarbons are brought into contact with rni'iltensub- -f stances or at any ratek with molten metals-orf .alloys for a certain, short period of time, ata" .certain temperature.. they are converted into lubricating oils and I ,have discovered means of. 1 producing-and maintaining the necessary conditions as regards the tirneelement,temperature.;` V

heat transfer, and contact, so that the reaction can be maintained indefinitely or at least to suchV an extent that such asprocess becomes of practical value. l l

The conversion of asphaltic hydrocarbons. by-

this process into lighter oils falling'malnly with' in the boiling point range of oils classed as lubri-,

eating oils, may be made highly efcient; that is. l

side reactions producing undesirable by-products ysuchaskflxed gases, coke or other valueless or detrimental products may .be largely suppressed 1;@ to give a substantially complete yield of lighter oils on the basis of the asphalt converted. However, as the time element is veryshortfit ls diming it separately. if necessary at a higher temperature.

As stated, the necessary time element is very short. This is controlled in part at least by keeping the amount of hydrocarbon material in the reaction zone to a minimum relative to the available contact surface.v If the unconverted. portion of the asphalt is not removed almost immediately, or within a certain time limit, depending on the temperature employed, it will polymerize and eventually decompose with the formation of carbon or coke, which carbonor coke will rapidly foul the contact medium or metal bath, in many cases within a few minutes, to such an extent that the converesion reaction of asphalt into lubricating oil will be completely arrested. despite the fact that the time element and temperature might be suitable for converf sion.

Whether the molten substance, such ss molten metal or alloy. called herethe contact medium. acts in the process disclosed here in the role of s catalyst, isnotcertain. 'As arule, the `reactions produced by catalysis are specific 'to certain substances. whereas to my knowledge the conversion reaction here can be brought about by..

contact with -any molten. substance. ,as far matassa short, is partly dependent on the exact nature of the asphaltic oil stock worked upon. on the temperature of the contact medium, on the temperature of the incoming oil, etc. However, the procedure necessary in each case will be made clear from the disclosures given further on. In general, `the contact period should be sumciently short to insure that the hydrocarbon material.

as a substance is used lthat does not en` v,

ter into chemical Areaction with the asphaltv typically unconverted asphalt, is not substantially decomposed into coke, nxed gas etc., auch decomposition being prevented by removing the asphalt before it reaches excessive temperatures or before substantial decomposition sets in due to protracted contact at elevated temperatures; orboth.

The proper, short time element for contact is accomplished, first by introducing the asphalt or oil containing it either upon the surface of the metal bath or ashort distance below it, such as a few inches. and second by rapid or immediate lremoval of the converted products from contact with the bata by rapid or immediate veintiuntion. induced by maintaining a sufilciently high temperature in the molten bath and employing 'any known means capable of( increasing the volatility of the oils produced. such as 4vacuumand/or carrier gases, but especially steam, inert gases, and the like, which I have found most effective and economical.

The use of steam or other eifective means of Y increasing volatility, is especially important from the viewpoint of immediately removing any uni converted asphalt from contact with the bath. if

' temperaturesappreciatly above 400 C. are mainheat is;` transferable from the molten metal to the small globules or iilms of asphalt material4 may be an important factor in the process. The depolymerization or conversion reaction by which asphaltis converted into lubricating oil may be initiated at elevated temperatures, but is appartained in the bath.V If temperatures below 400'` C. are maintained in the bath; it is however possible toallow theasphalt to remain in contact with the bath a somewhat longer period, so that ently endothermic in character, and a continued and rapid input'of heat is required to maintain this reaction 1in ascendancy over undesirableA side-reactions leading to degraded products, coke etc, Attempts to obtainthis rapid heat transfer through poorly conducting surfaces. e. g.. solid surfaces; wouldrequire such a high temperature differential as to resultin local over-heating and surface ydeposition, of coke, thus defeating further conversion. By the use of molten metal, however,

conversionsl at a hydrocarbon temperature oi 27 5 to 375 C. may be maintained with a temperaturemmerential such for example that the metal temperature need be only 450 to 550 C. The rapidity -Qf heat transfer is further aided by the agitationxor circulation of the molten metal.

duction otthefheat is 1ny were. instances 1t u advantageous 'to provide for the more or less abrupt heatingofthe asphalt to the desired'conversionj temperature; L e.. t0

avoid preheatingforfother pretreatment involving heating of thestcch` to elevated temperatures.

it may be allowed to float on top of the bath and is drained of! as rapidly as' possible. The steam may be introduced into the molten bath at any level, preferably at a lower ie'vei than the asphaltic rawI stock. The steam does not decompose or enter into reaction with the oil; the water re coveredin the condensate is equal to the water fed in as steam.

'Ihe feed stock need not be preheated when temperatures appreciably over 400 C. are maintained in the bath, but with lower temperatures. preheating of the stock becomesV advisable; in

which case a preheat temperature of 'about 250 y C. is sumcient to insure a high degree of con` version. Due to the short contact period the temperature of the oil or oil vapors is' not brought up to the temperature of the contact medium or bath, in fact a contact period should be established of only sumcient duration to heat the stock l to a point where the convertedhproducts. and in caseof higher temperatures in the bath also the unconverted asphalt, are volatilized with the aid ofsteam. Thetemperature of the vapors is usually around 300 C. It is to bestated here that with a high temperature'in thebath, such as, 'c

for instance 450 C. and over,`a ny unconverted asphalt is readily volatillzed together with the converted products, provided suilicient steam or other carrying gases and/or vacuum are used. despite the fact that the temperature of the vapors may not be over 300 C. This volatilization of asphalt under such conditions may not be due to actual z'aporization, butto mechanical carrying over, such as in the form of a fog.

I have found that in many instances my invention may be advantageously practiced with the molten metal at a temperamrepf 450" to 550 -perature .inthe alloy.

. alloy amounted lng a procedure. similar to theone turning the heavy, asphaltic 'bottoms back into the process with fresh feed stock. a complete conversion of the asphalt present in the crude oil was aecomplished. The converted distillate or asphalt-tree, overhead therefrom could-be variously utilized The lubricating oil fractions were equal or superior to thelubricating oil 'originally associated with the crude, and also constituted an excellent cracking stock for liquid o r vapor phase cracking, as well as a blending stock for fuel oils. i i

V l Example No. 2

The; same crude oil as-'in Example No. 1 was treated kby passing it through' a molten alloy; consisting-o'l 80%. of -leadandlofit of antimony, this alloy having a' meltingpoint sufficiently far below Vthe temperature employed in'thl oase to keep it sufiic'ientlyfiuidfatalltunes;f The. oil was' -prealloy tinchesbeiow the surface; The alloyrwaa .kept -at a' temperature of-3'10 C. and steam .nmountign'ito 40% lof thejcrude 'was introduced through another -feed line;

the-time required Vfor draining despite the. fact that under such conditionsit remains incontaot with the bath a longer period the asphalt is removed by volatilization. The asphalt or lresidue..drained on the surface of the to Aof theierude oil treated. The combined distillate` was'free .from asphalt. 'Bhe asphalt content was therefore reduced from '11% m1569721;` -No coke or gas formation took place and the totalfyield of voil and asphaltic residue was 100%. It was found that the remaining asphalt drained ofi the surface yof the bath could not be converted by returning itback into the process with freshfee'd stock.;- However. conversion ofthis residue was-accomplished-by employgiven under Example No.-1-and maintaining in the. bath a temperature `of :about 550' C.

rxmpleivd 3 An. Oklahoma 4crtule petroleum was used in this case. l'Ihisfcrude is extensively used for the about 5% of asphalt and when distilled in the ordinary. manner vproduces lubricating oil stocks which require .acid refining, with consequent heavy.losses,..before they'can bennisbed to a proper c olor with absorptive clays. distilledin a manner similar to theonegivenunder Example No. '1, except thatsthe temperature of theV lead bath was maintaineftlvat 4251" C. and the amount of steam usedwfailiil7a. The yield of oil recovered was.' approximately' 100% and no carbon or coke formationftooi ace. The lubricating oil stock producedlwasthen treated with absorptive clays withoutjl preliminary acid re- :ming 'and an ou witnss haard com was obtained, while the Alubriciaitn'ig 'oil' stock obtained from the same crude byordi'ary distillation methods could not be treated and finished with absorptive clays without preliminary acid refining.

This application is a continuation-impart of my copending applications, Serial Nos. 142,560

and 166,307.

heated tizso-chiiu introduced inte ,the .molten out as'rapidlyaspossible. 1 With-such a lowtemtheasphalt will otooke ine vbon ofthe character described t0 4lubricating I claim as-'my invention: i

1. A method of. converting asphaltic hydrocarbon of the character ydescribed `to lubricating oil, comprisingthe steps of: bringing said asphaltic hydrocarbon into substantially momentary contact with a body of molten metal maintained at such a temperature in the range of 450 to 550 C. that said asphaltic hydrocarbon will be brought to a temperature within the range of 275 to 375 C.; and dlsengaging the asphaltic hydrocarbon and resulting converted products brought to said temperature. from further contact with` the molten metal by-volatilization and atomizaticn in a concurrent now of both volatilized' and nonvolatilized portions with `steam so adjusted. that substantially no converted or un- -converted asphaltic hydrocarbon is left in contact with the molten metal for periods exceeding the desired momentary contact.

2. A method of converting asphaltic hydrocaroil comprising the steps of: bringing said asphaltic hydrocarbon into substantially momentary contact with a body of molten metal maintained at thanincaseswhere in a concurrent n of the metal; continuously said contact with such temperature that said asphaltic hydrocarbon will be brought to a temperature within its temperature range of conversion as the result of Y molten metal, whereby a substantially complete conversion of asphaltic sub- -stanceto lubricating oil isV obtained without substantial formation of coke, gas, or other reversion products; and disengaging the asphaltic hydrocarbon and resulting converted products'brought to said temperature from further contact with the molten'metal by volatilization and atomization flow of bothvolatilised and nonvolatilized portions with steam so adjusted that substantially no converted Vor unconverted asphaltic hydrocarbon is left in'contact with the molten metalfor periods in excess of the desired momentary contact.

3. A process for converting asphaltic stock of the character described into lubricating oil, comprisingz' maintaining a body of molten metal in a reaction zone at a temperature from about 375 to about 550 C.; agitating said metal by `introducing therein a stream of carrier gas and permitting said gasto escape from the upper surface bringing the asphaltic stock into said reaction zone to contact the molten metal at a level not lower than a few inches below the upper surface of the metal; adjusting the stream of carrier gas to volatilize lubricating oil manufacture oflubricating oils, but contains v fractions present in the stock and formed by conversion thereof to produce an' eiiiuent stream of gas andrhydrocarbon vapor having a temperature not greatly in excess of 300 C.; and continuously removing any non-volatile asphalt from the upper surface of the metal to prevent protracted contact thereof with the molten metal.

4. A process as in claim 3 stock is introduced into the reaction zone at a level not lower than four inches below the surface of the molten metal.

i 5. A process for converting asphaltic stock of lthe character described into lubricating oil, comprising: maintaining a body of molten metal at a temperature from about 375 to about 450 C.; introducing the asphaltic stock into said metal at a depth of not over a few inches from the upper surface thereof; introducing a stream of carrier gas into the body of molten metal to cause agitation thereof and to aid in the volatilization oi the lubricating oil; adjusting the relative rates of introduction of asphaltic stock and carrier gas in which the' asphaltic into the molten metal to cause complete and continuous volatilization at temperatures not greatly in excess of 300 C. of lubricating oil fractions produced by conversion of the asphalt in the presence of the molten metal; and continuously withdrawing non-volatile fractions accumulating on the upper surface ofthe molten metal.

6. A process for converting asphaltic hydrocarbons into lubricating oil, comprising the steps of: maintaining a body of molten metal in a reaction zone at a temperature from about 450 to about 550 C.; passing a current of steam therethrough; introducing the asphaltic hydrocarbon into said reaction zone at a level not lower than a few inches below the surface of the molten metal to contact the metal and induce at least partial conversion thereof into lubricating oil; and adjusting the current of steam to remove the asphalt and conversion products from the molten metal in a concurrent stream of vapors and atomized particles. l

7. A method of converting asphaltic hydrocarbons into lubricating oils, which comprises the steps of: continuously bringing said asphaltic hydrocarbons into contact with the surface of a body of molten metal; maintaining the temperature ofthe metal in the range from about 450 to' 550 C.; and continuously disengaging the resulting converted.` product and any unconverted hydrocarbon from contact with the molten metal by volatilization4 and atomization in a concurrent now of both volatilized and unvolatilized por-- tions with a stream of a carrier gas, so adjusted that substantially no converted or unconverted hydrccarbons are left in contact with the molten metal beyond a momentary period.

8. A method as in claim 'I in which the stream of carrier gas is adjusted to scavenge the surface of the molten metal and maintain it substantially clean, whereby the quantity of hydrocar- 5 bon material in contact with the molten metal at a given instant is minimized.

9. A method of converting asphaltic hydrocarbons of the character described into lubricating oils, comprising: continuously bringing the l asphalticA hydrocarbons into contact with the surface of a body of molten metal; maintaining the temperature of the metal above 450 C,; and removing'the converted and any unconverted hydrocarbons from contact with the metal by l` volatilization and atomization in a concurrent i'low with a stream of a carrier gas so adjusted that the temperature of the ellluent stream of v vapor and gas does not substantially exceed 300 C.

1.0. A method of converting asphaltic hydrocarbons of the character described into lubricating oil. which comprises: bringing the asphaltic hydrocarbons continuously into contact with the surface of a body of molten metal maintaining the temperature of the metal in a range from about 350 C. to 450 C.; agitating said metal with a current of carrier gas adjusted to produce an emuent stream comprising gas and hydrocarbon vapor, the temperature of said stream being not greatly in excess of 300 C.; and continuously removing any non volatile asphalt from the upper surface of the metal to prevent protracted contact thereof with the molten metal.

VAINO A. BALMI. 

